================================================================== BUG: KASAN: use-after-free in __nft_trace_packet+0x135/0x150 net/netfilter/nf_tables_core.c:30 Read of size 2 at addr ffff888025ba4e40 by task ksoftirqd/1/20 CPU: 1 PID: 20 Comm: ksoftirqd/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 __nft_trace_packet+0x135/0x150 net/netfilter/nf_tables_core.c:30 nft_trace_verdict net/netfilter/nf_tables_core.c:110 [inline] nft_do_chain+0x12a5/0x14f0 net/netfilter/nf_tables_core.c:256 nft_do_chain_inet+0x25c/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x1f2/0x390 include/linux/netfilter.h:300 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5551 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5665 process_backlog+0x370/0x790 net/core/dev.c:6542 __napi_poll+0xc0/0x430 net/core/dev.c:7101 napi_poll net/core/dev.c:7168 [inline] net_rx_action+0x4d4/0xa10 net/core/dev.c:7258 handle_softirqs+0x339/0x830 kernel/softirq.c:576 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 20: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] synproxy_send_client_synack+0x16f/0xde0 net/netfilter/nf_synproxy_core.c:482 nft_synproxy_eval_v4+0x347/0x4e0 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x304/0x570 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x48c/0x14f0 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x25c/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x1f2/0x390 include/linux/netfilter.h:300 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5551 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5665 process_backlog+0x370/0x790 net/core/dev.c:6542 __napi_poll+0xc0/0x430 net/core/dev.c:7101 napi_poll net/core/dev.c:7168 [inline] net_rx_action+0x4d4/0xa10 net/core/dev.c:7258 handle_softirqs+0x339/0x830 kernel/softirq.c:576 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 20: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 nft_synproxy_eval_v4+0x34f/0x4e0 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x304/0x570 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x48c/0x14f0 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x25c/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x1f2/0x390 include/linux/netfilter.h:300 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5551 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5665 process_backlog+0x370/0x790 net/core/dev.c:6542 __napi_poll+0xc0/0x430 net/core/dev.c:7101 napi_poll net/core/dev.c:7168 [inline] net_rx_action+0x4d4/0xa10 net/core/dev.c:7258 handle_softirqs+0x339/0x830 kernel/softirq.c:576 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff888025ba4dc0 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 128 bytes inside of 232-byte region [ffff888025ba4dc0, ffff888025ba4ea8) The buggy address belongs to the page: page:ffffea000096e900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25ba4 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 0000000b00000001 ffff888144bf0140 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 4190, ts 67886507320, free_ts 67885103103 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] kmem_cache_alloc_node+0x1c3/0x2d0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] netlink_sendmsg+0x654/0xbe0 net/netlink/af_netlink.c:1893 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x46d/0x620 net/socket.c:2072 __do_sys_sendto net/socket.c:2084 [inline] __se_sys_sendto net/socket.c:2080 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2080 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 mm_free_pgd kernel/fork.c:653 [inline] __mmdrop+0xaa/0x3e0 kernel/fork.c:704 mmdrop include/linux/sched/mm.h:49 [inline] finish_task_switch+0x215/0x640 kernel/sched/core.c:4948 context_switch kernel/sched/core.c:5052 [inline] __schedule+0x11f7/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093 do_wait_for_common+0x2a2/0x450 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion_killable+0x48/0x70 kernel/sched/completion.c:243 call_usermodehelper_exec+0x435/0x520 kernel/umh.c:440 call_modprobe kernel/kmod.c:98 [inline] __request_module+0x40b/0x980 kernel/kmod.c:170 dev_load+0x156/0x1b0 net/core/dev_ioctl.c:433 dev_ioctl+0x3c0/0xe30 net/core/dev_ioctl.c:498 sock_do_ioctl+0x245/0x320 net/socket.c:1161 sock_ioctl+0x4d2/0x710 net/socket.c:1266 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 Memory state around the buggy address: ffff888025ba4d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff888025ba4d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888025ba4e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888025ba4e80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff888025ba4f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================